Portable hand drill



B. W. BENBOW PORTABLE HAND DRILL Filed June 28, 1949 May 5, 1953 ATTORNEY-5 !NVENTOR Patented May 5, 1953 UNITED STATES OFFICE 3 Claims.

This. invention relates to portable hand drills such as are operated by electric or pneumatic motors.

In the use of such portable drills the operator usually grips the handle provided thereon and holdsthe drill to the work piece with sufficient pressure to obtain the proper cutting action. Frequently, however, this operation is difiicult and unsatisfactory. For example, when the device is being used overhead or at head height, it has been. found difiicult to hold the drill steady and apply proper force simultaneously, without unduly tiring the operator. Again, when such drills are used. by an operator standing upon a ladder, it. is frequently impossible, for the operator to apply sufficient pressure to the drill from his positionto perfect a cutting operation. The same situation exists whenever the operator is in an awkward or cramped position.

The foregoing difiiculties have made extensive use of portable drills difficult under certain conditions and at times have rendered their use unsafe.

It is an object of the present invention to provide a novel device by means of which the drill may be urged against the work piece and held in operative position with respect thereto with the minimum amount of exertion by the operator.

Another object of the invention is to generally improve upon portable drills of the above character, particularly with respect to providing improved means for urging the bit aganst a work piece, and to provide a relatively simple structure which can be manufactured without undue cost and which can be readily manipulated by inexperienced operators.

Further objects and advantages of the present invention will appear from the following specification taken in conjun tion with the accompanying drawings in which:

Figure 1 is a side elevational view of a drill incorporating my invention.

Figure 2 is a cross-sectional detail taken along the line 2-2 of the device shown in Figure 1.

Figure 3 is a cross-sectional detail of the device taken along the line 3-3 of Figure 2; and

Figure 4 is a cross-sectional detail taken alon the line 4-4 of Figure 2.

As shown in Figure 1, I have provided a conventional drill consisting generally of a housing I!) adapted to support a conventional driving means such as an electric or pneumatic motor. The housing It] is provided with a handle H by which the operator holds the device and a trigger member H by which the motor i started and stopped. The motor drives a chuck l3 which is adapted to grip a drill It.

At the top of the housing It] I have provided a reel mechanism which will more fully hereine after be described and which is adapted to be operated by means of a handle it. The reel mechanism is adapted to support a chain or cable ll, one end of which is secured to the reel and which is adapted to be wound thereon and the other end of which is provided with a hook it, the use of which will be more fully hereinafter described. The cable I! may be passed through a tubular member is which is secured to the housing it and which serves as a guide for the member H.

The reel mechanism heretofore referred to is shown in greater detail in Figures 2, 3 and 4. As illustrated, it consists of a circular casing 2| wh ch may be suitably secured to the housing In by means of a base 22 thereon, which may be fastened to the housing It by any suitable means. The casing 2! is provided with an opening 23 which is adapted to receive a stud shaft 24. As shown in Figure 2 the stud shaft 2 is provided with a shoulder 26 which abuts the inner surface of the casing 2! adjacent the edge of the opening 23. A nut 2'! is engaged with the threaded portion of the stud shaft 24, and urges the shoulder 25 against the wall of the casing 2| toretain the same in cooperative relationship therewith.

Rotatably mounted upon the stud shaft 24 I have provided an annular reel member 28 which is provided with an annular slot 29 adapted to receive a cable ii and around which the cable I1 may be reeved. The end of cable E1 remote from the hook I8 is dead ended on the reel 23.

The reel 28 is also provided with a centrally disposed recess 3! within which a coil spring 32 is mounted. One end of the coil spring 32 is provided with an opening 33 which cooperates with a pin 34 upon the sleeve 35 and the other end of the spring 32 is provided with an opening 35 which cooperates with a pin 31' upon the wall of the recess 3! by means of which it is operatively connected to the reel 23.

I have also provided an annular cut-away drum portion A! which provides an annular wall 42 which acts as a clutch face, in that the same cooperates with a helicoidally wound spring wire 43. One end of the spring wire 43, as shown in Figure 3, is secured to the lever I6. The other end of the spring wire 43 is provided with an outturned end portion 33a, and is adapted to abut a shoulder Zia formed on the casing 2|.

The member 45 is provided with an opening 48 and is rotatably mounted upon the free end of shaft 24. This member carries the sleeve 35 to which the spring 32 is attached.

Normally the spring wire snugly engages the annular wall 42. When the handle I6 is actuated (downwardly as viewed in Figure 1) and the spring 43 is rotated, the spring grips the wall 42 and will, consequently, cause the rotation of the entire reel 28. When the handle I 6 is moved in the opposite direction the engagement of the spring 43 and the face 42 is automatically released and the reel 28 will be actuated only by the member I! and the spring 32. For the limiting position shown in Figures 1 and 3, the end portion 43a strikes the shoulder 2Ia to slightly unwind the spring wire 43 and thus release the reel for free spooling in either direction.

Operation of the device may briefly be described as follows: The drill I4 is placed in engagement with the work piece. A length of cable I I is withdrawn and the hook I8 engaged with the work (Figure 1). When the hook I8 is secured the spring 32 will have been wound slightly tighter and will tend to wind the member I1 back upon the reel 28 and take up any slack in the member I'I. During this time the clutch means formed by spring wire 43 and its associated drum is disengaged because spring 32 also urges handle I6 to its uppermost position with portion 43a being urged against the shoulder 2Ia. Actuation of the handle I6 downwardly about the shaft 24 will cause the spring 43 to engage the face of the annular wall 42. This action will cause the reel 28 to rotate with the handle I6 about the shaft 24 and will apply pull to the cable II. Pull on the cable I I will be transferred to the shaft 24 which, it should be pointed out, is directly above the center line of the drill I4 whereby any pressure upon the handle I6 which is transferred to the cable I! will be directly in line with the drill I4.

When the drilling has been completed, the handle I6 moves upwardly, whereby the clutching effect of the spring 43 upon the face of wall 42 is automatically terminated, and the reel 28 is free to be rotated. The cable I! may now be withdrawn sufiiciently to permit it to be freed from the work piece, and the tension of the spring 32 will cause the cable I I to be wound upon the reel 28 until the hook I8 comes in contact with the lower end of the tubular guide member I9.

It will be appreciated that the member I 6 may be actuated any number of times during the drilling of a single hole. In other words, when the member I! has been wound upon the sheave 28 by the action of the handle I6 to such an extent that no further pressure is being applied to the shaft 24 and the drill I 4, action of the handle I6 in the opposite direction will declutch the same from the reel 28 until the handle I6 is again moved downwardly at which time a clutching action occurs, as has previously been described, and further pressure is applied to the member 24.

Reference is made to my co-pending application Serial No. 648,671, filed February 19, 1946, for Hand Drill, now abandoned.

I claim:

1. In a portable drill comprising a motor, a chuck adjacent one end of and driven by the motor, the chuck being adapted to hold a bit, a reel mounted on the motor and having its axis intersecting the extended axis of the bit, a cable wound upon the reel and adapted to have one end of the same connected to a work piece, a lever pivotally carried by the motor for movements in opposite directions between limiting positions, and clutch means serving to operatively connect said lever to said reel, whereby when the lever is moved in one direction said reel is turned to tension the cable and thereby urge the drill against the work piece, said clutch means comprising a helicoidally formed spring wire, and a drum carried by the reel and about which the spring wire engages, one end of said spring wire having an operative attachment with said lever.

2. A portable drill as in claim 1 in which the free end of said helicoidally formed spring wire is formed to engage a relatively fixed abutment shoulder when the lever is in its one limiting position to thereby free the reel for rotation in either direction.

3. A portable drill comprising a motor, a chuck adjacent one end of and driven by the motor, the chuck being adapted to hold a bit, a reel mounted upon the motor, a pull cable wound upon the reel and having its free end adapted to be extended for attachment to a work piece, a spring operatively connected to the reel and urging the same to rotate in a direction to wind up the cable, an operating lever pivotally carried by the motor on an axis coincident with the axis of the reel and movable in opposite directions between limiting positions, one end of said spring being attached to said lever whereby said lever is normally urged toward its one limiting position, and clutch means serving to operatively connect the lever to the reel whereby the reel can be rotated to tension the extended cable when the lever is moved from said one limiting position, said clutch means comprising a drum carried by the reel, and a helicoidally formed spring wire engaging the periphery of the drum, one end of said wire being attached to said lever, and a stationary shoulder adapted to engage the other end of spring wire when said lever is in said one limiting position.

BURTIS WILLIAM BENBOW.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 390,029 Lombard Sept. 25, 1888 1,184,829 Crist May 30, 1916 1,220,564 Schlagel Mar. 27, 1917 

